As the distribution of the Windows Phone-based Lumia smartphones ramps up, Nokia is still dependent on the sales of Symbian-based smartphones. But that isn't working so well. Sales are dropping faster than expected, Nokia said.

"Despite the latest improvements on Symbian's user interface and a few new devices launched, it is now clear that Nokia will not be able to continue relying on Symbian and needs to move even faster to Windows Phones," said Jeronimo.

Milanesi agrees: Symbian's weakness is putting more pressure on Nokia to make the transition to Windows Phone faster.

During 2011, Nokia progressed in the right direction, but it still has a tremendous amount to accomplish in 2012, it said in a statement.